The principle objective of a diagnosis is not to categorise symptoms, or group a combination of signs or clinical symptoms in a coherent way, but to cure a patient or improve their quality of life. Diagnoses that are technically correct, but do not seek this objective may become unnecessary labels which convert healthy people, or those who do not consider themselves to be sick, into patients. We propose a limitation of the diagnostic effort in order to reduce the iatrogenic consequences of these unnecessary labels or diagnoses, a new imperative which, in Kantian terms, can be expressed as: examine and treat your patients in such a way that, at the very least, the effects of your actions always improve the quality of their lives